To easily and accurately attach a flexographic printing plate to the attaching bar connected to a plate cylinder.

A carrier sheet 14 having an attaching plate 10 and the flexographic printing plate attached thereto is registered to be attached to a plate cylinder. The attaching bar 10 and the carrier sheet 14 have a plurality of openings 30, 46 arranged so as to be certainly coaxially superposed one upon another between the attaching bar 10 and the carrier sheet 14. The opening 30 of the attaching bar 10 is coaxially superposed on the opening 46 of the carrier sheet 14 and, by inserting a fixing pin 56 into the coaxially superposed opening 50, the fixing pin is registered to be fixed to the attaching bar 10. Further, a method for attaching a flexographic printing plate includes a device for holding one end part of the carrier sheet 14 so as to obstruct the movement of a plurality of openings during the formation of the openings.